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HttpClient.PostAsJsonAsync crushed without exception

I am trying to call an api(POST method) with HttpClient.PostAsJsonAsync. However, it stopped at httpClient.PostAsJsonAsync without any exception.
The source code as below:
public static async Task<oResult> PostApi(string JSON_sObject, string sEnd_Url) {
oResult oResult = new oResult();
var Data = JsonConvert.DeserializeObject(JSON_sObject);
var Url = "http://localhost:44340/" + sEnd_Url;
HttpClient httpClient = new HttpClient();
try {
httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage response = await httpClient.PostAsJsonAsync(new Uri(Url), Data); // it stopped here
if (response.IsSuccessStatusCode)
{
var sResponse_content = await response.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<oResult>(sResponse_content);
}
else
{
return oResult;
}
}
catch (Exception ex)
{
LogFile(ex);
return oResult;
}
}
Please advice me if any issue from the source code.
Thank you

you should not trying serialize deserialize twice
remove from your code
var Data = JsonConvert.DeserializeObject(JSON_sObject);
and replace
HttpResponseMessage response = await httpClient.PostAsJsonAsync(new Uri(Url), Data);
with this
var content = new StringContent(JSON_sObject, Encoding.UTF8, "application/json");
var response = await client.PostAsync(sEnd_Url, content);
also fix base httpclient address
var baseUri= #"http://localhost:44340";
using HttpClient client = new HttpClient { BaseAddress = new Uri(baseUri) };
try {

Send Json as body and file webrequest

How to send both body and also a file?
From the API Guide: "Upload Requests are submitted with multiple parts: body (request) and file buffer (file)."
I know how to send only a Json as body, but I need now to seng Json as body and also a file.
My code looks something like:
const string WEBSERVICE_URL = "https://myurl.com";
var webRequest = System.Net.WebRequest.Create(WEBSERVICE_URL);
webRequest.Method = "POST";
webRequest.ContentType = "multipart/form-data;boundary=12345678912345678912345678";
webRequest.Headers.Add("Authorization:7786FFFGFDDDP");
And:
string json="{"\some json"\ :\"here\" }"
using (var streamWriter = new StreamWriter(webRequest.GetRequestStream()))
{
streamWriter.Write(json);
}
var httpResponse = (HttpWebResponse)webRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
Console.WriteLine(result.ToString());
}
But how to send both file and body together? I mean I want also to upload some file wih path #c:\\myFile.txt

I need to do this in a Xamarin application. Post an image to a web api with token based authentication. I made some changes in code to be posible use in a web application.
public async void SendFile()
{
using (System.IO.FileStream stream = System.IO.File.Open(#"c:\file.txt", System.IO.FileMode.Open))
{
var content = new System.Net.Http.MultipartFormDataContent();
content.Add(new System.Net.Http.StreamContent(stream),
"\"file\"",
"Path to your file (ex: c:\temp\file.txt");
await PostItemAsyncWithToken("url to post", content, "accessToken");
}
}
public async System.Threading.Tasks.Task<bool> PostItemAsyncWithToken(string url, System.Net.Http.HttpContent content, string accessToken)
{
try
{
using (var httpClient = new System.Net.Http.HttpClient())
{
httpClient.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", accessToken);
System.Net.Http.HttpResponseMessage response = await httpClient.PostAsync(url, content).ConfigureAwait(false);
if (response.IsSuccessStatusCode)
{
return true;
}
else
{
return false;
}
}
}
catch (System.Exception ex)
{
throw new System.Exception("Error message", ex);
}
}

Converting: `system.net.http.httpresponemessage` to `system.io.stream` in C#

My CurrentCode:
using (var client = new HttpClient
{
Timeout = TimeSpan.FromMilliseconds(2000)
})
{
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var response = await client.GetAsync(new Uri(Constants.mUrl));
// convert stream to string
StreamReader reader = new StreamReader(respons);
var myItems = Newtonsoft.Json.JsonConvert.DeserializeObject<ModelClassObject>(response);
return myItems;
}

Use ReadAsStreamAsync on the content of the response
using(var response = await client.GetAsync(new Uri(Constants.mUrl))) {
var stream = await response.Content.ReadAsStreamAsync();
//...
}
If you want to parse JOSN directly from the response, then
using(var response = await client.GetAsync(new Uri(Constants.mUrl))) {
var myItems = await response.Content.ReadAsAsync<ModelClassObject>();
return myItems;
}

Xamarin Forms Json Service Insert Data

I want to add a record to the json service in my application. How can I do this via Service Url. Here is my code.
CustomerModel customer = new CustomerModel();
customer.Name = entryCompanyName.Text;
customer.Title = entryCompanyTitle.Text;
customer.PhoneNumber = entryTelephone.Text;
customer.FaxNumber = entryFax.Text;
customer.Email = entryEmail.Text;
customer.CityId = 6444;
string json = JsonConvert.SerializeObject(customer);
string sContentType = "application/json";
string path = "service url";
HttpClient Client = new HttpClient();
var task = Client.PostAsync(path, new StringContent(json.ToString(), Encoding.UTF8, sContentType));
I'm trying M. Wiśnicki's solution, but I took this error
I did not get an error when I added System.net :( Where do i make mistakes?

This worked for me
public static async Task<string> PostEntityToApi<T>(string yourMethodUrl, T yourModel)
{
try
{
if (_httpClient == null)
{
_httpClient = new HttpClient { BaseAddress = new Uri(yourWebSiteUrl) };
}
var stringContentInput = new StringContent(JsonConvert.SerializeObject(dto), Encoding.UTF8, "application/json");
var response = await _httpClient.PostAsync(new Uri(yourWebSiteUrl. + apiUrl), stringContentInput);
if (!response.IsSuccessStatusCode)
{
throw new Exception(response.StatusCode.ToString());
}
var stringAsync = await response.Content.ReadAsStringAsync();
LoggingManager.Error("Received error response: " + stringAsync);
return stringAsync;
}
catch (Exception exception)
{
return null;
}
}

You can use WebRequest, this sample working for me, i use it in my app.
This is System.Net.WebRequest class, here you find doc.
public async Task<string> PostSample(object data, string uri)
{
// Create an HTTP web request using the URL:
var request = (HttpWebRequest) WebRequest.Create(new Uri(uri));
request.ContentType = "application/json";
request.Method = "POST";
var itemToSend = JsonConvert.SerializeObject(data);
using (var streamWriter = new StreamWriter(await request.GetRequestStreamAsync()))
{
streamWriter.Write(itemToSend);
streamWriter.Flush();
streamWriter.Dispose();
}
// Send the request to the server and wait for the response:
using (var response = await request.GetResponseAsync())
{
// Get a stream representation of the HTTP web response:
using (var stream = response.GetResponseStream())
{
var reader = new StreamReader(stream);
var message = JsonConvert.DeserializeObject<string>(reader.ReadToEnd());
return message;
}
}
}

POST Request UWP

I writing UWP app.
I need to send POST request with json to server
Here is my code for downloading JSON and writing to value:
public async void AllOrders_down()
{
string url = "http://api.simplegames.com.ua/index.php/?wc_orders=all_orders";
var json = await FetchAsync(url);
List<RootObject> rootObjectData = JsonConvert.DeserializeObject<List<RootObject>>(json);
OrdersList = new List<RootObject>(rootObjectData);
}
public async Task<string> FetchAsync(string url)
{
string jsonString;
using (var httpClient = new System.Net.Http.HttpClient())
{
var stream = await httpClient.GetStreamAsync(url);
StreamReader reader = new StreamReader(stream);
jsonString = reader.ReadToEnd();
}
return jsonString;
}
How I need to send POST request with this json to server?
Thank's for help.

Here is an example Post request that I have used in a UWP application.
using (HttpClient httpClient = new HttpClient())
{
httpClient.BaseAddress = new Uri(#"http://test.com/");
httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
httpClient.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("utf-8"));
string endpoint = #"/api/testendpoint";
try
{
HttpContent content = new StringContent(JsonConvert.SerializeObject(yourPocoHere), Encoding.UTF8, "application/json");
HttpResponseMessage response = await httpClient.PostAsync(endpoint, content);
if (response.IsSuccessStatusCode)
{
string jsonResponse = await response.Content.ReadAsStringAsync();
//do something with json response here
}
}
catch (Exception)
{
//Could not connect to server
//Use more specific exception handling, this is just an example
}
}

You should be using httpClient.PostAsync().